The Effect of Beta-Blockers on a Course of Chronic Heart Failure in Patients With a Low Triiodothyronine Syndrome

OBJECTIVE: The aim: The aim is to study the effect of β-ABs in patients with LT3 S on the course of HF. PATIENTS AND METHODS: Materials and methods: 354 patients with HF on a background of post-infarction cardiosclerosis were included in the 2-yeared follow-up study. LT3 S was diagnosed at 89 (25.1%) patients. The levels of thyroid-stimulating hormone, free T3f and T4f, and reversible T3 were determined. The echocardioscopy was performed. RESULTS: Results: Patients with HF in combination with LT3 S have a heavier functional class by NYHA, greater dilatation of the left heart cavities, less myocardial contractility, a higher frequency of atrial fibrillation and re-hospitalization. The use of β-ABs in patients with HF without LT3 S leads to a likely decrease in hospitalization frequency, while in patients with LT3 S it has an opposite effect. The frequency of rehospitalization increases with an excess of β-ABs dose > 5 mg (equivalent to bisoprolol). At these patients a decrease in serum T3 level and negative dynamics of parameters of intracardiac hemodynamics are observed. CONCLUSION: Conclusions: The use of β-ABs in patients with LT3 S leads to an increase in re-hospitalization at a dose over 5.0 mg (equivalent to bisoprolol). In these patients there is a decrease in serum T3, an increase in T4 level; and the ejection fraction decrease; and heart cavities size increase.